The Senate will vote this week on the Marketplace Fairness Act, he says.

Senator Harry Reid (D, NV), the majority leader, told the Senate today that it will remain in session through the end of this week if necessary to vote on the Marketplace Fairness Act, which would broadly extend the number of Internet and catalog retailers required to collect state sales taxes.

Reid’s testimony on the floor of the Senate today came as other senators opposed to the bill gave lengthy arguments against it, prompting the majority leader to warn his colleagues that the current legislative session will run through this Saturday if necessary. “I caution my colleagues, the Senate will stay in session until we finish this legislation, whether that happens today, tomorrow, Friday or Saturday,” he said, adding that the Senate will have other pressing matters to address when it comes back in session after next week’s recess. “Unfortunately, there a few senators who want to play procedural games with this bill.”

Although Reid didn’t name those senators, among those speaking against the bill today were Democratic Senators Ron Wyden and Jeff Merkley of Oregon, who contend that because Oregon doesn’t have a sales tax Oregon-based retailers shouldn’t have to collect sales tax in other states. The bill seeks to overturn existing federal law by allowing states to require Internet and catalog retailers to collect sales tax. Under existing law, states can only mandate sales tax collection by retailers with an in-state physical presence like stores or distribution centers. The bill exempts retailers doing less than $1 million a year in remote sales, or sales in states where they have no physical presence.

Meantime, more than 10 amendments to the bill were submitted today, including one from Senator Jeanne Shaheen (D, NH) that proposes an exception from the bill for retailers based in states without a sales tax, including New Hampshire, Oregon, Delaware and Montana.

Another amendment, by Senator Merkley, calls for retailers in states without their own sales tax to get reimbursed for the cost of collecting and remitting sales tax in other states.

Senator Dick Durbin (D, IL), a co-sponsor of the bill with Senator Mike Enzi (R, WY), expects the Senate will approve the bill this week, a spokeswoman for Durbin says. Last month, the Senate voted 75-24 in favor of a non-binding resolution to support the bill, and earlier this week the Senate voted 74-20 to begin debating it on the Senate floor. Those two votes were viewed as indications that the bill is likely to pass in the Senate. Opponents, however, say they expect it will face stiffer opposition in the House.